Because of the hazardous nature of ammonium nitrate (AN), there are existing federal regulations for its safe handling and storage. The Occupational Safety and Health Administration’s (OSHA) Explosives and Blasting Agents Standard (29 CFR 1910.109) includes coverage of fertilizer grade AN. OSHA is considering whether or not to modify this standard or to add AN to their list of chemicals subject to their Process Safety Management (PSM) standard, which could result in the standard applying to processes at fertilizer mixers, distributors and wholesalers who store and handle AN. The DHS is also considering potential modifications of its CFATS regulation involving modification of screening threshold quantities (TQs) for chemicals of interest, which includes AN.
Given these factors, EPA will continue to work closely with OSHA and DHS to determine whether additional EPA action is necessary. Although EPA is not proposing to add AN to the list of substances subject to the RMP rule at this time, the Agency may elect to propose such a listing at a later date.